The proposed Missouri Valley Cancer Consortium (MVCC) will be a multi- component community-based cancer research effort based in Omaha and Lincoln, Nebraska. The catchment area includes western Iowa and east- central Nebraska. The 1990 population was about 1.2 million. The Omaha affiliate has been commended as one of the largest accruers of patients in the North Central Cancer Treatment Group. The--four main components of the MVCC would be: Bergan Mercy Medical Center, Langdon & Block, P.C., Lincoln Cancer Center, and the Creighton Cancer Center. These institutions have had an established research program with the North Central Cancer Treatment Group (NCCTG) since 1983. Numerous investigators (33) participate and are responsible for over 2,990 new cancer patients annually. Over the past 10 years, these investigators have entered 1,628 patients on NCCTG protocols alone with recent average of 285 patients annually. In 1992, these investigators entered 191 and 94 patients on NCI-approved cancer treatment and control trials, respectively. The proposed principal and associate principal investigators of the MVCC are currently directing the conduct of the Breast Cancer Prevention Trial (97 accrued to date) and the Prostate Cancer Prevention Trial (initiation 10/93) for the state of Nebraska. Current research base affiliations with NCCTG, ECOG, and NSABP would continue and enable the future support of this high level of accrual as a NCI-funded CCOP.